An electric arc furnace is a device that uses the thermal effect of an electric arc to heat the charge for smelting steel. Electric arc furnace steelmaking is the main method for producing medium and high alloy and high quality steels.
Electric arc furnace steelmaking uses electric energy as the heat source, which avoids the pollution of the steel by the sulfur contained in the gas heat source. The operation process is flexible, and both slag and furnace gas can be adjusted to be oxidizing or reducing. The strong reducibility can make the precious elements such as chromium, nickel, tungsten, molybdenum, vanadium and titanium contained in the charge to be rarely damaged by burning. High furnace temperature, easy control and high product quality.
Electric arc furnace steelmaking uses scrap steel as the main raw material. According to different slag-forming materials, there are alkaline methods and acid methods. The most commonly used is the alkaline method.
Alkaline operation method of electric arc furnace steelmaking
(1) Double slag method. It is suitable for smelting with high phosphorus content in the charge and large oxidative dephosphorization tasks. After the charge is melted, slag with high basicity and high oxidizing property is firstly produced, and at the same time of dephosphorization, it is decarburized, degassed and heated to the temperature required for reduction refining. After the oxidative refining meets the requirements, the oxidized slag is scraped off, and the high-basicity reduced slag is regenerated for desulfurization and deoxidation. There are two types of reducing slag: white slag and carbide slag. The former is white and easy to pulverize after cooling, and is suitable for smelting steel with a carbon content of less than 0.35%. In addition to lower FeO, the latter also contains 22% to 4% CaC, hence the name calcium carbide slag, which has stronger reducibility and is suitable for smelting high carbon steel parts.
(2) Single slag method. The slag is only made once, and the two refining requirements are met by adjusting the slag composition. This method is only suitable for smelting with low phosphorus content in the charge and light dephosphorization task. Since the phosphorus content in the slag after dephosphorization is low, it can be directly decarburized and heated to reduce refining without changing the slag. In order to avoid the oxidation loss of alloy elements in the return smelting of some high-alloy scrap steel, only reduction refining can be performed without oxidation. For some ordinary carbon steels that do not have high requirements for reduction refining, they can also be only used for oxidation refining. When the composition is qualified and the temperature is raised, the steel can be tapped. Both are single-slag methods.
Acid operation method of electric arc furnace steelmaking
The electric arc furnace is lined with acid refractory materials, and the smelting process produces acid slag saturated with SiO2. The slag does not have the ability of desulfurization and dephosphorization, and the scrap steel is required to contain sulfur and phosphorus below the specifications of the steel being smelted. Therefore, there are few sources of scrap and high prices, which limit the development of sour operations. The characteristics of acid operation are: low slag conductivity, fast heating and high electrical efficiency. The acid slag and SiO2 in the furnace lining have high activity at the steelmaking temperature, and are easily reduced by carbon, aluminum, titanium, zirconium, etc. in the charge. The reduction period mainly relies on the reduction of SiO2 in the slag to deoxidize, which is called silicon reduction deoxidation. The acid method has a shorter steelmaking cycle than the alkaline method, and is mostly used in steel casting workshops.
Electric arc furnace melting furnace manufacturer
Yushun Metallurgy Co., Ltd. is an excellent exporter of metal smelting equipment. With decades of rich experience in electric furnace development, we can provide various advanced and efficient solutions for electric arc furnace steelmaking. Production of various specifications and types of electric arc furnaces, such as steel casting with grooved electric arc furnaces, top charging electric arc furnaces, horizontal continuous charging electric arc furnaces, top electric arc preheating furnaces, ferroalloy electric furnaces, stainless steel electric arc furnaces. As well as providing related process, automation and environmental protection systems. If you want to know more products, please visit our website and contact us.